1. Field of the Invention
The present invention generally relates to semiconductor integrated circuits, and more particularly, the present invention relates to an input/output buffer having analog and digital input modes.
2. Description of the Related Art
In order for a semiconductor device to support multimedia applications which include video and audio processing, it is necessary that the device be equipped to handle both analog and digital signaling formats. Recently, mixed integrated circuits (mixed IC's) have been developed in which analog and digital circuits are embedded in one chip so as to provide single-chip multimedia processing. In a mixed IC, signals are of different types are transmitted and/or received through separate signal pads. For example, analog signals may be input/output on one signal pad, and digital signals input/output on another signal pad. Unfortunately, however, the use of multiple pads in this manner results in an increase in the overall area occupied by the chip. This makes it difficult to achieve levels of miniaturization generally demanded in the semiconductor industry.